Abnormal ultrasound appearance of the amniotic membranes – diagnostic and significance: a pictorial essay

The obstetrical ultrasound may identify the protrusion of the uterine surface or placental area into the amniotic cavity. The differential diagnosis of this pathology with uterine adhesions, septate uterus, circumvallate placenta, amniotic band or amniotic sheet can be sometimes difficult. The purpose of the pictorial essay is to exemplify the presence of the amniotic sheet and circumvallate placenta in routine obstetrics screening of all trimesters of pregnancy.